The present invention relates to 4-(N,N-dialkylamino)aniline compounds having a 4-N substituent which is a polyethyleneoxy group and which forms a condensed ring with benzene ring, a processing composition containing such a compound and a method for forming a color image with the processing solution.
4-(N,N-dialkylamino)aniline compounds are useful as a developing agent for a silver halide color photographic material and they are described in, for example, Japanese Patent Unexamined Published Application (hereinafter referred to as "J.P. KOKAI") No. Hei 5-257248, 6-161061 and 7-36162.
As mini-labs for processing photosensitive materials within the shops and the amount of color negative films used in the field of news photos are increasing recently, the demand for completion of the development process in a shorter time to immediately provide the prints to the customers or to immediately place the photo in newspapers or the like is rapidly increasing. The demand for reduction of the processing time is becoming more and more eager in processing color negative films, since the time necessitated therefor is longer than that necessitated for processing color papers.
For the reduction of the time necessitated for the color development step in the processing steps, J.P. KOKAI No. Hei 4-45440 discloses a method wherein tetrahydroquinoline or a dihydroindole derivative is used as the color developing agent. The use of such a compound as the color developing agent is also described in U.S. Pat. Nos. 2,196,739 and 2,566,259. In particular, it is described in J.P. KOKAI No. Hei 4-45440 that the time necessitating for the color developing step can be reduced by using such a compound as the color developing agent even in color photograhic photosensitive materials mainly comprising a silver bromoiodide emulsion such as color negative films. Further, it is described in European Patent No. 670,312A1 that when at lease one of three carbon atoms forming the propylene chain of tetrahydroquinoline skeleton is free from hydrogen atom, the fog density is lowered.
However, it was found that the development of a photosensitive material for color photography with one of the compounds described in these specifications has some defects. Namely, since the image density in the unexposed part is high to cause a fog, the yellow and cyan image densities are insufficient as compared with the magenta image density in the exposed part, and the three-colors are not well balanced.
Polyethyleneoxy groups having two or more repeating units are not described in the description or in the examples of the compounds as a 4-N substituent of a tetrahydroquinoline compound or dihydroindole compound in the above-described J.P. KOKAI No. Hei 4-45440, U.S. Pat. Nos. 2,196,739 and 2,566,259 and European Patent No. 670,312A1. Not only in the compounds usable as the developing agent for silver halide color photographic materials but also in known 4-(N,N-dialkylamino)aniline compounds in which a 4-N substituent is capable of forming a condensed ring with a benzene ring such as te trahydroquinoline compounds and dihydroindole compounds, there are no compounds having a polyethyleneoxy group having two or more repeating units as N-substituent.